create and attach a console to a windows application for cin/cout

attach_to_console.cpp

#include <windows.h>

#include <stdio.h>
#include <stdlib.h>

// Function prototypes.
LRESULT CALLBACK WndProc( HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam );
int WINAPI WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR szCmdLine, int iCmdShow );

// In a C++ Windows app, the starting point is WinMain().
int WINAPI WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR szCmdLine, int iCmdShow )          
{

  // these next few lines create and attach a console
  // to this process.  note that each process is only allowed one console.
  AllocConsole() ;
  AttachConsole( GetCurrentProcessId() ) ;
  freopen( "CON", "w", stdout ) ;

  printf("HELLO!!! I AM THE CONSOLE!" ) ;


  WNDCLASSEX wc = { 0 };
  wc.cbSize = sizeof( WNDCLASSEX ) ;
  wc.cbClsExtra = 0;  // ignore for now
  wc.cbWndExtra = 0;  // ignore for now
  wc.hbrBackground = (HBRUSH)GetStockObject( WHITE_BRUSH );
  wc.hCursor = LoadCursor( NULL, IDC_ARROW ); 
  wc.hIcon = LoadIcon( NULL, IDI_APPLICATION );
  wc.hInstance = hInstance;
  wc.lpfnWndProc = WndProc;
  wc.lpszClassName = TEXT("Philip");
  wc.lpszMenuName = 0;
  wc.style = CS_HREDRAW | CS_VREDRAW; // Redraw the window

  RegisterClassEx( &wc );

  HWND hwnd = CreateWindowEx( 0, TEXT("Philip"), TEXT("window's title!"), WS_OVERLAPPEDWINDOW, 10, 10, 200, 200, NULL, NULL, hInstance, NULL );      

  ShowWindow(hwnd, iCmdShow );
  UpdateWindow(hwnd);

  MSG msg;

  while( GetMessage( &msg, NULL, 0, 0 ) )
  {
    TranslateMessage( &msg );
    DispatchMessage( &msg );
  }

  return msg.wParam;    // return from WinMain
}

LRESULT CALLBACK WndProc( HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam )
{
  switch( message )
  {
  case WM_CREATE:
    // upon creation, let the speaker beep at 50Hz, for 10ms.
    Beep( 50, 10 );
    printf("HELLO!!! I AM THE CONSOLE!" ) ;
    return 0;
    break;

  case WM_PAINT:
    {
      // we would place our Windows painting code here.
      HDC hdc;
      PAINTSTRUCT ps;
      hdc = BeginPaint( hwnd, &ps );

      // draw a circle and a 2 squares
      Ellipse( hdc, 20, 20, 160, 160 );
      Rectangle( hdc, 50, 50, 90, 90 );
      Rectangle( hdc, 100, 50, 140, 90 );
      printf("HELLO!!! I AM THE CONSOLE!" ) ;

      EndPaint( hwnd, &ps );
    }
    return 0;
    break;

  case WM_LBUTTONDOWN:
    printf("STOP POKING MEEE!!!\n") ;
    break;

  case WM_DESTROY:
    PostQuitMessage( 0 ) ;
    return 0;
    break;

  }

  return DefWindowProc( hwnd, message, wparam, lparam );
}

create and attach a console to a windows application for cin/cout

references:

https://bobobobo.wordpress.com/2009/03/01/how-to-attach-a-console-to-your-gui-app-in-c/

https://www.codeproject.com/Articles/15836/Writing-to-and-read-from-the-console-From-a-GUI-ap

https://www.codeguru.com/cpp/w-d/console/redirection/article.php/c3961/Windows-Applications-that-Have-Access-To-Console-Features.htm